Green Blog: The Physics of Tidal Energy

Chris Becker for The New York Times Looking down the shaft of a tidal turbine as a worker readied it for operation. It will be lowered to the bottom of Cobscook Bay off Eastport, Me. As my colleague Jess Bidgood reported in Friday’s paper, a tidal energy project is moving ahead in Maine, with high costs but high hopes too. But the 180-kilowatt unit that Ocean Renewable Power Company hopes to put under water next week is really just a first step. The big question is, how well will it withstand the force of the rushing water? The region, the Bay of Fundy, is famous for strong tides, but the company has picked a spot called Cobscook Bay, where the current is relatively slow, an average of 5.8 knots, or 6.7 miles per hour. That is the speed at which the hardware will produce 180 kilowatts. If the equipment performs well there, the next step is for the company to put a similar ...